Process of catalytically reducing anthraquinone compounds and new hydrogenized products derived therefrom



Patented May 13, 1930 UNITED STATES PATENT OFFICE JULIUS VON BRA'UN .AND OTTO BAYER, F FRANKFORT-ON-THE-MAIN, GERMANY,

ASSIGNORS '10 GENERAL ANILINE WORKS, INCL, OF NEW YORK, N. Y., A CORPORA- TION OF DELAWARE rnoonss or C(ATALYTICALLY nnnuciiwe ANTHRAQUINONE ooMPoUNDs AND-raw HYDROGENIZED rnonuo'rs DERIVED THEREFROM No Drawing. Original application filed February 27, 1926, Serial No. 91,227, and. in GermanyMarch 3,

19,25. Divided and this application filed June 10, 1927. Serial No. 198,006.

Our invention relates to a new process of catalytically reducing anthraquinone comquinone compounds, different productsof distinct degrees of hydrogenation can be prepared. If anthraquinone-is subjected to this process, in the first phase of the reaction anthranol or anthrone) is obtained with a practically quantitative yield. In the second phase of reaction tetrahydroanthranol, and by allowing to react still a further quantity of hydrogen, octohydroanthranol is obtained. The final product of the catalytical reduction is octohy'droanthracene.

- All the known base metal reduction or hydrogenation catalysts are suitable for our process, but we have found the mixturesof catalysts prepared for instance by precipitating an aqueous solution of a mixture of nickel sulfate, cobalt sulfate and copper sulfate by means of a carbonate of soda solution to be especially effective;

By the expressions base metal reduction catalysts and base metal hydrogenation catalysts we purpose to include those known catalytic agents of reduction and/or of hydrogenation which contain one or more of the base metals, which base metals are present in the catalytic agent either in their ele mental form or in the form of their respective oxides or salts.

The new process is not limited to anthraquinone itself, as also derivatives of anthraquinone, for example alkly-, hydr0xy-, n1tro-, amino-anthraquinonesnaphthan-thraquinone etc. easily can be catalytically reduced in the described manner.

In'order to obtain the higher hydrogenized compounds one may start, instead of'from an anthraquinone compound itself, from the anthranol body as the next step of hydrogenation.

The new products are intended to be used as starting materials for the production of dyestuffs and therapeutical products. The following examples illustrate the nature of our invention and in what manner it is to be performed, the parts being by weight and all temperatures in degrees centigrade.

Example 1 A solution of 52 parts of anthraquinone 1n v 100 parts of decahydronaphthalene is treated in an autoclave at 160-170 C. with hydrogen in the presence of a mixture of carbonates of nickel, iron and copper as catalyst, until a quantity of hydrogen is absorbed corresponding to 12 atoms. In this manner pure octohydroanthranol is obtained in a good yield,

which compound separates from the partly evaporated solution of the reaction mass. The new colorless compound corresponding to the formula:

H2 Hz 8H H2 Hz (octohydroanthrenol) B 0 H2 I which melts at 124 C. is diflicultly soluble in alkalies and yields an acetyl compound melting at 52 6., a benzoyl compound melting at 128 C. and a monobromo-derivative melting at 123 C. It couples with diazocompounds to form azodyestufl's. By oxidizing it with chromic acid a yellow quinone is formed having the melting point of 180 C.

Emample- 2 If 1i4-dimethylanthraquinone is subjected to our process, a new compound of the octohydroa'nt'hranol step, having probably the formula:

- on, H! E l H H H:

l: l H

o (1.4-dimethyl-octohydroanthranol) is obtained. It crystallizes from ligroin as colorless needles melting at 83 84 C.

As final product of the catalytic reduction the hydrocarbon is obtained.

In the following-we give some statements relating to reduced derivatives of other anthraquinone compounds, which all can be obtained according to our process of catalytic reduction. Among the further hydrogenized derivatives of tetral-2.3-anthraquinone of the formula 4 a H2 ll obtainable by condensing tetrahydronaphthalene with phthalic acid anhydride and acting with sulfuric acid on the ortho-(tetroyl- 2-) benzoic acid thus formed. (See Berichte d. Deutsch. Chem. Ges., Vol. 54, page 2244) may be mentioned: i

H: OH H H:

(2.3.6.7-bis-tetramethylene-alpha naphthol) I crystallizing from glacial acetic acid as yeldecahydronaphthacene, melting at 82 (3., and

perhydronaphthacene, melting at about 50 C Among the hydrogenized derivatives of beta-hydroxy-anthraquinone may be named for example:

(beta-hydroxy-octo-hydroanthranol) tion of an anthraquinone compound in the presence of a base metal hydrogenation catalyst with substantially twelve atomicproportions of hydrogen.

2. Process of producing an octohydroanthranol compound which comprises acting under pressure upon one molecular proportion of an anthraquinone compound, with the addition of an organic diluent, in the presence of a base metal hydrogenation catalyst with substantially twelve atomic proportlons of hydrogen.

3. Process of producing an octohydroanthranol compound which comprises acting under pressure and at elevated temperatures upon one molecular proportion of an anthraquinone compound in the presence of a base metal hydrogenation catalyst with substantially twelve atomicproportions of hydroen. 4. As a new product octohydroanthranol of the formula:

z m n H,

which is soluble in alkalies and the usual or ganic solvents, yields a'zo dyestufis when combined with diazo compounds and forms acetyl-, benzoyl-, and a mono-bromo-substitution product.

In testimony whereof we alfix our signatures.

JULIUS VON BRAUN. OTTO BAYER. 

